Description of problem:
An attempt to print a string representation of a CoprResponse instance causes a traceback.


Version-Release number of selected component (if applicable):
python-copr-1.58-1.fc21.noarch


How reproducible:
always


Steps to Reproduce:
1. from copr.client import CoprClient
2. cl = CoprClient.create_from_file_config()
3. prj = cl.get_project_details('dnf')
4. unicode(prj)


Actual results:
Traceback (most recent call last):
  File "/tmp/stack/dnfstackci.py", line 974, in <module>
    _start_commandline()
  File "/tmp/stack/dnfstackci.py", line 784, in _start_commandline
    unicode(prj)
TypeError: coercing to Unicode: need string or buffer, dict found


Expected results:
Successful conversion of the instance to a Unicode string.


Additional info:
Originally, I discovered when trying to "print(prj)" which causes:
Traceback (most recent call last):
  File "/tmp/stack/dnfstackci.py", line 974, in <module>
    _start_commandline()
  File "/tmp/stack/dnfstackci.py", line 784, in _start_commandline
    print(str(prj))
  File "/usr/lib/python2.7/site-packages/copr/client/util.py", line 15, in __str__
    return self.__unicode__().encode('utf8')
AttributeError: 'dict' object has no attribute 'encode'

The problem is probably here: https://git.fedorahosted.org/cgit/copr.git/tree/python/copr/client/responses.py#n65
I guess the return value should be converted to a string.